Comment 6 for bug 1649066

good point about favs. maybe the download queue & hash files would be of concern as well?

could we handle them through some upgrade step? could be done outside of the XML parsing code, launched for these "precious" files when the XML parser encounters a validation error?
some best effort to replace by question marks or ascii equivalents, and an error message when all else fails... it is important no user loses settings (especially favorites) when upgrading.